Editing Guadalcanal campaign (section)

===Air battles over Henderson Field and strengthening of the Lunga defenses===
{{Further|Cactus Air Force}}
[[File:HendersonF4FIntercept.gif|thumb|U.S. Marine [[Grumman F4F Wildcat]]s from Henderson Field preparing to attack incoming Japanese aircraft in late August or early September 1942]]

Throughout August, small numbers of American aircraft and their crews continued to arrive at Guadalcanal. By the end of August, 64 planes of various types were stationed at Henderson Field.<ref>Zimmerman p. 74</ref> On 3 September, the commander of the [[1st Marine Aircraft Wing]], U.S. Marine Brigadier General [[Roy Geiger]], arrived with his staff and took command of all air operations at Henderson Field.<ref>Hough p. 297</ref> Air battles between the Allied aircraft at Henderson and Japanese bombers and fighters from Rabaul continued almost daily. Between 26 August and 5 September, the U.S. lost about 15&nbsp;aircraft to the Japanese's approximately 19. More than half of the U.S. aircrews shot down were rescued; most of the Japanese aircrews were not. The eight-hour round-trip flight from Rabaul to Guadalcanal, about {{convert|1120|mi|km}}, seriously hampered Japanese efforts to establish air superiority over Henderson Field. Throughout the campaign, Rabaul-based Japanese aircrew had to fly almost 600 miles before combat with Allied pilots operating in the immediate area of Henderson Field. The Japanese navy also did not systematically rotate their veteran pilots out of combat zones. This steadily exhausted and depleted Japanese air power in the region. From a strategic standpoint, the overall quality of Japanese aviation in the Solomons deteriorated as worn-out veteran pilots were replaced by inexperienced aircrew with minimal combat experience. Australian coastwatchers on [[Bougainville Island|Bougainville]] and [[New Georgia]] islands were often able to provide Allied forces on Guadalcanal with advance notice of approaching Japanese air strikes, allowing the U.S. fighters time to take off and position themselves to attack the Japanese aircraft as they approached. The Japanese air forces were slowly losing a [[Attrition warfare|war of attrition]] in the skies above Guadalcanal.<ref>Frank, pp. 194–213; and Lundstrom, p. 45. In comparison to the {{convert|560|mi|km}} separating Lunga Point from Rabaul, Berlin was about {{convert|460|mi|km}} from Allied air bases in eastern England. Later United States Admiral of the Fleet, William F. Halsey, paid tribute to Australian Coastwatchers: "The Coastwatchers saved Guadalcanal, and Guadalcanal saved the South Pacific."</ref><ref>{{cite web |url=http://www.arrl.org/news/behind-enemy-lines-an-amateur-radio-operator-rsquo-s-amazing-tale-of-bravery |title=Behind Enemy Lines: An Amateur Radio Operator's Amazing Tale of Bravery |website=[[American Radio Relay League]] }}</ref>

During this time, Vandegrift continued to direct efforts to strengthen and improve the defenses of the Lunga perimeter. Between 21 August and 3 September, he relocated three Marine battalions, including the [[Marine Raiders|1st Raider Battalion]], under [[Merritt A. Edson]] (Edson's Raiders), and the [[Paramarines|1st Parachute]] Battalion from Tulagi and Gavutu to Guadalcanal. These units added about 1,500 troops to Vandegrift's original 11,000 men defending Henderson Field.<ref>Morison, ''The Struggle for Guadalcanal'' p. 15; and Hough, p. 298.</ref> The 1st Parachute Battalion, which had suffered heavy casualties in the Battle of Tulagi and Gavutu–Tanambogo in August, was placed under Edson's command.<ref>Smith, p. 103; Hough, p. 298.</ref>

The other relocated battalion, the [[1st Battalion, 5th Marines|1st Battalion, 5th Marine Regiment]], was landed by boat west of the Matanikau near Kokumbuna village on 27 August with the mission of attacking Japanese units in the area, much as in the first Matanikau action of 19 August. The Marines were impeded by difficult terrain, hot sun, and well-emplaced Japanese defenses. The next morning, the Marines found that the Japanese defenders had departed during the night, so the Marines returned to the Lunga perimeter by boat.<ref>Zimmerman, pp. 78–79</ref> These actions resulted in the loss of 20 Japanese and 3 Marines.<ref>Frank, ''Guadalcanal'', p. 197.</ref>

Small Allied naval convoys arrived at Guadalcanal on 23 and 29 August, and 1 and 8 September to provide the Marines at Lunga with more food, ammunition, aircraft fuel, aircraft technicians, and other supplies. The convoy on 1 September also brought 392 [[Seabees]] to maintain and improve Henderson Field.<ref>Smith, pp. 79, 91–92, 94–95.</ref> In addition, on 3 September, [[Marine Aircraft Group 25]] began airlifting high-priority cargo, including personnel, aviation gasoline, munitions, and other supplies, to Henderson Field.<ref>Armstrong, ''Marine Air Group 25 and SCAT'', pp. 23–26.</ref>